- #1
KingNothing
- 882
- 4
I have held the dream for a long time of LEDs being controlled by an audio signal. You know, when the music gets louder, the LED gets brighter. Not just 'fully on' or 'fully off', but different levels of brightness. However, I don't know how to build this circuit.
I think the audio signal would have to be split into two paths one going to the speakers and the other going to the circuit. The circuit would be powered and light up the LED, but be controlled by the audio signal.
Okay, so the 'power supply' part would have to be controlled by the varying AC voltage of the audio signal. Let's just establish some numbers for the LEDs to make the discussion consistent: 2600mcd intensity, forward max voltage 3.3V, forward max DC current: 30mA, max reverse voltage 5V.
I know a few basic concepts of electronic circuits, but I'm jumping in feet-first to try to learn. I know several camera batteries have a voltage rating of three. I suspect this would be the proper way to power the LED (along with a current-limiting resistor), but unfortunately I don't have any bright ideas on how to get an audio signal to control a power supply to make it supply different voltages.
In theory, I imagine something the audio signal controlling something like a potentiometer (used as a voltage divider). What I mean is, imagine that the audio signal could turn the nob on a potentiometer which divided the voltage supplied by the power supply – moving the slider all the way to the positive terminal when the audio signal is “loud”, and all the way to the negative when the audi signal is “quiet”. Problem is, the audio signal obviously cannot physically turn the knob or move the slider on a potentiometer. Is there some sort of other voltage-divider that could be controlled by a compelx AC signal such as audio?
Thanks ahead of time for the help!
Edit: on second thought, Would it be better cost-wise to use a 9V battery and two resistors to divide the voltage drop into 3 and 6, then just use the 3V as the main power for the LED? (the 3V would be what is controlled by the signal, just brainstorming)
I think the audio signal would have to be split into two paths one going to the speakers and the other going to the circuit. The circuit would be powered and light up the LED, but be controlled by the audio signal.
Okay, so the 'power supply' part would have to be controlled by the varying AC voltage of the audio signal. Let's just establish some numbers for the LEDs to make the discussion consistent: 2600mcd intensity, forward max voltage 3.3V, forward max DC current: 30mA, max reverse voltage 5V.
I know a few basic concepts of electronic circuits, but I'm jumping in feet-first to try to learn. I know several camera batteries have a voltage rating of three. I suspect this would be the proper way to power the LED (along with a current-limiting resistor), but unfortunately I don't have any bright ideas on how to get an audio signal to control a power supply to make it supply different voltages.
In theory, I imagine something the audio signal controlling something like a potentiometer (used as a voltage divider). What I mean is, imagine that the audio signal could turn the nob on a potentiometer which divided the voltage supplied by the power supply – moving the slider all the way to the positive terminal when the audio signal is “loud”, and all the way to the negative when the audi signal is “quiet”. Problem is, the audio signal obviously cannot physically turn the knob or move the slider on a potentiometer. Is there some sort of other voltage-divider that could be controlled by a compelx AC signal such as audio?
Thanks ahead of time for the help!
Edit: on second thought, Would it be better cost-wise to use a 9V battery and two resistors to divide the voltage drop into 3 and 6, then just use the 3V as the main power for the LED? (the 3V would be what is controlled by the signal, just brainstorming)
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